Synthesen in der Polymyxin‐Reihe 2. Mitteilung. Synthese eines Dipeptid‐Fragmentes mit (+)‐Isopelargonsäure

Abstract
(+)‐6‐Methyloctanoic (isopelargonic) acid, the fatty acid component of certain polypeptide antibiotics known as polymyxins, has been synthesized by a new route, starting from (−)‐2‐methylbutanol‐(1). The protected dipeptide Nα‐(+)‐Isopelargonyl‐Nγ‐benzyloxycarbonyl‐D‐α,γ‐diaminobutyryl‐L‐threonine, corresponding to the side chain of two structures which have been proposed for polymyxin B1, was obtained by known peptide coupling methods.